Combination air compressor and vacuum pump



`April za, 1925,' 1,535,856

- i E. A. Rm

COMBINATION AIR COMPRESSOR AND VACUUM PUMP l Filed May l5, 1924 3 Sheets-Sheet 1 irme/ltorl E. A. am COMBINATIN AIR COMPRESSOR AND VACUUM PUMP Amm za, 1925; Y f. l 1,535,856

Filed May 15, 1924, s sheets-smet' 2 Qu/Maf Mw/ m i @y Q7/wmf f 074 UX l April 28, 1925i.

-L-A. mx

COMBINATION AIR QOMPRESSOR AND VACUM PUMP Filed May '15 1924 s sheets-shet s hole/'Maf 1f/M4 MQW@ lil

muren sTA'iEs' issues@ earner' orties..

nnvvann A. minor een' rneisorsco, mirriron-ure.'"

.pplication died May l5,

To all fui/loin t may concern.'

Be it 1Known that lEnWnnn Rrr, a citizen ot the United States, residing at the city and county of San Francisco and State ol California, have invented new and useful liiiprovements iii Combination Air Compressors and Vacuum Pumps, of which the 'following is a specification.

This invention relates to acomhination air compressor and vacuum pump, and to an automatic regulating' device therefor. y

Service stations for 'automobiles are cominon and nui'nerous and they are becoming more audniore a necessity as far as the motoringpublic is concerned.

Considerable competition exists between the. service stations olf dilierent oil companies and otherwiseand the stations are as a re-y sult becoming forced to. install elaborate equipment, such as air compressing units, etc.,A to Abe in a position to render every assistance possible. 'Practically every station is equipped with an air compressing unit and tanks to permitintlation of tires, ctc., anda considerable number of stations are equipped with so-called visible dispensing' machines which require a vacuum pump to elevate' the gasoline from the submerged storage tanks to the visible containers, `from which thegasol'ne fis 'delivered by gravity to the tanks of the' autoinobiles.

The air compressors anc vacuum pumps are usually driven by independent electric motors and are automatically actuated to the extent that a. variation in pressure or vacuum will, make orbreak the motoren'- ciu't and as such automatically maintains predetermined lpressures or vacuums. Such ,actuating mechanisms.

installations require Aseparate compressors and vacuum pumps, and similarly separate electric motors, with connected automatic The installations are as aresult costly; .theyrequire `'coi'isiderable space, which is often an important factor, and While they areV automatic in operation, a certain amount of attention, repair, etc., is nevertheless required.A

The object of the present invention is'to providein a singleunit a combined air lcompressor and yacuum pump which is driven'by a single ,electric motor," and to 4'provide an automatic control whereby the motor circuit will be actuated loothy by the compressed air and thewvacuum, and which will furthermore permit the compressor and the .'vacuum pump to'a'ct in unison or indevalve 8 of-the high pressure cylinder.

mi. sensi ne. meer.

.gether with the tanks connected therewith and the electric ihotor driving the same, said unit also showing the position of the automatic controlling mechanism whereby the circuit through the motor is automatically opened and closed.,

Fig. 2 ispan enlarged detail sectional view of the vacuum reliet valve.

' Fig. 3 is a central vertical longitudinal section through the combined vair compressor and vacuum pump.

Fig. is a diagrammatic View showing; the wiring diagram employed.

Fig. 5 is e central vertical longitudinal section through one of the switch controlling units.

6 is a. central. vertical cross-settion taken on line idw-ii, Fig. 5. l

Fig. 7 is a vertical cross-section taken on line 77, Fig. i3.

l-tefeiring` to the drawings in detail, and particularly to Figi' 3, A. indicates a low pressure air compressing cylinder, 2 the head, 3' the low pressure inlet Valve, 4 the 'low pressure discharge valve, 5 'an intercooler, '6' a pipe connecting;r theasame with the low pressure Idischarge.valve. a high pressure cylinder, if a cylinder head, 8 the inlet valve, 9 the high pressure discharge valve, 10 a secondintercooler, and il a pipe connecting,r thev saine with the discharge valve 9 of the high pressure cylinder. The inlet valve of the high pressure cylinder, indicated at 8, is connected with the interu cooler 5 through means of al pipe `-12,and the low pressure air discharged by the valve d is thus lay-passed throng-h the pipe. @fthe intercooler 5 and the pipe 12 to tlhe'ii'rlet e iflsd with pistons, as indicated at 13 and 145i these pistons being connected by a connecting;` yokel 15. The compressor is otherwnje p'rovided with a crank case 16 to avhiclh the The respective cylinders are respective cylinders are attached ih? amy suitable manner. A crank shaft 17 is'liour- 'a trunk type piston and that it is Cil 'l e structure so lar described is more or -,ss common and discloses nothing more oli/less than a two-stage air compressor. By careful inspection of Fig. it will, however, be noted that the piston 13 is erably elongated; further, that a step or 'nilargement is formed at the point lt), and 1hat a secondary' piston of larger area is thus produced. This piston travels in a cylinder C, which is interposed between the crank case and the low pressure cylinder A; the cylinder C being attached to the crank case by a llange and bolts as indicated at 2() and the low pressure cylinder being in turn secured to the outer end of the cylinder C by a flange and bolts as indicated at 21.

' The cylinder andthe piston 19 operating therein torni a` vacuum pump, air be ing admitted to thisxpump from a tank 22 through means ot' pipes 23 and 24. The pipe .24 connects with an annular chamber 25 formed in a head 9.6 of the cylinder C. This head is also provided with a ring valve 2T which is adapted to automatically open and close a` series of ports 28. The piston 19 is similarly provided with a ring valve Qt) which is adapted to alternately epen and close a series of ports formed in the piston proper. Ports 28 are opened to admit air to the cylinder C when the piston travels in the direction of arrow a; ports il() being simultaneously closed by the ring valve 29. During the reverse movement ot the piston, valve 27 closes and valve 2S) opens. The air previously admitted is thus transferred to the other side ot' the piston 1Q and it is discharged into an annular chamber 31 and is .there permitted to escape through a pipe during the next stroke of the piston. Tank 22 may thus be evacuated to any degree desired but the exact amount of Vacuum that should be maintained is, however, regulated by an automatic aetuatingmechanism lwreinal'ter to be described, and also by means olA a poppet valve 33 (see Figs. l and L'). This valve is interposed between the pipes 2S) and Q4. lt is normally held` on its seat by means ot aY weighted lever -l: the weight being so adjusted that the valve will be maintained on its seat until a.predetermined vacuum is created. The air will thus be valveu'ill then litty and automatiealhY admitted to prevent the buildingI up ol' :i l'urthei' vacuum. The autO-. matie actuatingy mechanism just referred to will also function at this time and its eonstriu-tiou and operation will later be described.

the intercooler 10 is delivered to a tank indicated at B5 through means of a pipe 36 (see Fig. 1), and means are employed for Amaintainiiig a predetern'iined air pressure in the tank. 'lhis means is automatic in operation and its construction will be more clearly described by referrine to Figs. 5, 6 and 7.

Before entering into a detail discussion of the construction ot' this mechanism, it might be well to state that the combined compressor and vacuum pump here illustrated is driven by means of an electric motor such as indicated at 8'?, the p wer of the motor being transmitted to the crank shaft or" the compressor by means of e. be t 38 and a driving pulley lt might also be well to state that the circuit through motor is controlled by two separate mechenisms, generally indicated at 40 and 41 (see Figs. l and 4). The mechanism in'dicad at 40 is controlled hy the air pressure in the tank 35, and the mechanism illustrated at 41 is controlled by the vacuum maintained in the tank 22. Both of these controlling mechanisms are substantially iden* tical in construction `and function, and the description or' one should therefore suffice. These mechanisms control a pair of switches, diagranm'iatically illustrated at 42 and 43. These switches are connected in parallel, thc .switch 43 having two main terminals 44 which are connected with the power circuit through means of feed wires 45. rEhe opposite terminals of the switch 43, indicated at 46, are connected through wires 4T with the motor 3 The second switch indicated at 42 is provided with a pair of main terminals 48 which are connected through wires 49 with the feed wires 45, and the second set. of terminals in switch 42 is connected directly with the feed wires of the motor.

By providing this parallel connection it is possible to open one switch or the other without breaking the circuit through the motor, and it is impossible to break the circuit through the motor without opening both switches. The switches, as previously stated, are actuated by the automatic controlling vineflianisms indicated at 40 and 4l, and the structure of these mechanisms will now he described.

Again referring to Figs. 5, G and 7, it will be noted that a easing 40 is illustrated. One end of the casing is provided with a flexible. diaphragm 5() disposed between two head members 51 and 52. An air tight chamber 553 is thus `t'orn'ied on one side oft the diaphragm and this chamber is connected through means ot a pipe 54- \\'ith the pressure receiving tank li. The diaphragm is provided with a plate and a button such as indicated at 55 and the button extends through an opening in the head member 5l.

Lacasse l-t it is desired to maintain an air pres-` sure of 120 pounds inthe tank 35, the tension ot the spring 59 1s seregulated that the diaphragm will. not loe able topiinpart a.l rocking` movementto the lever 7 until this pressure is exceeded; that is, chamber 53 is in constant communication with the tank through means of pipe 54 and similar pressures are thus maintained on one side of the dialfihragm 53 and in the. tank 35. When this pressure is exceeded spring' .'59 yields and a rocking movement is thus imparted to' the lever 57 tliroiigh means of the diaphragm and the button This rocking movement serves the function of opening the switch 42 (see Figs; ft and 5), the move ment being transmitted through a yoke 6l,

'a pair of. levers G21 and 53, and a connecting link (i4. rThe lever 63 is pivotally attached to the lever 57 and its outer end is rovided with a roller which is normal y mainm tained in engagement with a notch 66 formed in the lower endet the link 6d, the roller being maintained in this position icy means ot a spring 67 and also by a second springA 68 which isattaclied to the lever .57 at Cpue end and to the link 64 at the opposite en lVhen lever' 57 moves downwardly', due to expansion ot the diaphragm, roller rides downwardly over the notched end of the link 64 and the moment it passes over the point 69 it strikes an inclined Jrace 70, time. freeing the link Gel. The inclined face ZO permits thel spring 68 tofunction and it thus imparts an upward movement to the This movement is' link (ifi and the lever 62. quick and snap-like and it is in turn transmitted to litt the yoke v61 and the switch 42 carried thereby. lVhen the air pressure drops in the tank 35, and consequently in the chamber 53, the tension of the spring 59 overcomes the pressure exerted on the dia-` phragm and lever 57 is pulled upwardly. This movement causes roller 65 to ride upwardly on the inclined end 70 of link 64 and when it pass'esover the. high point 69 a quick downward movement is iimparted'to the link-6l, lever 62 and yoke 61, this movement being' in'ipartedhy meansot spring 68. lhis downward movement again closes the switch 42. lhe switch is accordingly automatically opened and closed with varia tions inlair pressureand a predeterminedly pressure may -thus be niaintained.

The actuating mechanism indicated at 4l is substantially identical in construction to` that illustrated in Figs. 5, Gland 7, the only difference being1 that the position of the head members 50 and 5l is reverse, and that chamber :'33 is connected with the vacuum tank. Vln other words, a suction is produced in chamber 53 and this vexerts a pull on the diaphragm andimpart-s movement thereto, the movement beingtransmitted through a link which is connected with lever 5T. The mechanism il will thus automatically maintain a predetermined vacuum in the tank v22 as switch is opened and closed hy varia* tions of vacuum maintained in tank 22. In other Words the automatic actuatingl mechanism indicated at 40 serves the function of maintaining a predetermined air pressure in the tank 35, While the actuating` meclianism indicated at 41 maintains a predetermined vacuum in the tank These mcchanisms in turn actuate the switches e2 and 415 and as the motor circuit is controlled thereby, it can readily he seen that the circuit tlirough the motor will he automatically opened and closed as required and that continu-ous 4operation will not be required.

To further illustrate the operation of the combined compressor and vacuum lpump here illustrated, and the 'functioning of the controlling mechanism indicated at 40 and Lil, it ivill be assumed that it is desired to maintain 120 pounds air pressure in tank 35 and a 2O inch vacuum in the tank 22. 1f the vacuum is less than 22 inches'and the yair4 pressure is less than 120 pounds, both switches Ll2 and 13u/'ill be closed. The cir-l evacuated condition oi 20 inches `will be automatically maintained. The. high and low pressure compressing' cylinders 'A and B will continue to' operate and air under pressure will continue to. be delivered to the tank o5 until a pressureiot' 120 pounds is reached. The diaphragm 5.0 (see Fig, 5) will then expand, due .to the fact that it will. overcome the. tension of the spring'f), and switch 4t2 will thus he opened and as the .switch 4S has alreadybeen opened it can be seen that the circuit lthrough the motor '3T willhe broken and the unit as a Whole" 'will' come to rest.

If the pressure or vacuum drops, one ori another otfftlie'switches l2 or 43 will be closed und the circuit through the motori the pipeQLi through the valve and an will thus be closed and the unit will again be set in operation. lt can, therefore, be seen that the circuit may be closed by either oi the switches, but the circuit will not be broken except when both switches are opened. rlhis is important as it peri'nits either the compressing unit or the vacuum pump to function iiulcpcndently otz cach other even though they are operated and driven in unison. For instance` ii". a pressure oi 120 pounds .is obtained in the tank 3a before the desired evacuated condition is obtained in tank 22, it will be seen that switch't will be opened. Switch 4125, however, remains closed as the desired vacuum is not obtained. The unit, therefore, oontinues to operate as the motor circuit is not broken` but the air pressure in tank 35 will not be increased` as the relief valve is opened which permits the air 'from the eyinders A and B to be disclosed to the. atniosphere. This relief valve is best illfustrated in Fig. 7. It is mounted on the casing it) and in appearance resembles an elbow fitting. It is provided with an inlet connection 72 and an outlet connection 73, The inlet is conneeted through means oi a pipe 74 with the intercooler lo, while the connection 7 3 may be opened directly to the atmosphere. A check valve 75 is interposed between the connections and is normally retained ou .its seat by means of the air pressure and also by means of al spring' 7G. The valve is provided with a downwardly projecting stem 77 and this is in turn mounted in alignment with a pin 78. This pin is also illustrated in Fig. 5 and it forms a 'pivotal connection between the levers 62 and the link G4.

The lever 62 moves upwardly when switch 42 is opened and as switch 42 is not opened until the desired air pressure is obtained, it can he seen that this movement may be utilized to open the relier" valve 75. In other words the valve 75 is only opened when the switch is opened and it is merely opened for the purpose oi: permittingT the air discharged by the compressing cylinders to esca pe freely to the atnu'isphere when tank 35 has been charged to a predetermined pressure.

Valve 75 is not in communication with the tank 85 as the air from the intereooler is delivered to the tank through the pipe indicated at 3G. This pipe is provided with a cheek valve generally indicated at 80 and no air can thusl escape from the tank when valve 75 is opened as it is coi'mected with the. opposite end ot` the intercooler through thc pipe 74.

'I`hc unit as a whole is simple and compact in constructirm and requires comparativel)v little space: this boing: particularly true when it is considered that most semice stations or plants rcuuiriutx4 vacuum and compressed air service employ two scpar motor drivcn units, one beine' an air coni- Lacasse pressing' aait. and the other a vacuum pumping' unit. In other words the assembly shown in the present application requires, practically speaking'. only one-halt' the spaceg' the amount o'lA mechanism liable to 2gjet out ot order is substantially reduced to one-half; the cost is reduced, and as the operationof the structure as a whole is automatic comparatively little attention is required.

XVhiIe cert-ain features of the present invention are more or less specifically illustratt-d, I wish it understood that various changes in t'orin and proportion may be resorted to within the scope of the appended claims. I similarly wish it understood that the materials and finish of the several parts employed may be such as the experience and jiulg'mont of the manufacturer may dictate or various uses may demand.

l'iaviirt,r thus described my invention, what I claim and desire to secure by Letters Patent is- 1, A device oi the character described, comprising' a pair of cylinders, a. piston in each cylinder, one cylinder serving as an air compressor and `the other as a vacuum pump, a tank for the reception of the compressed air, a tank connected with the second cylinder and adapted to he evacuated thereby, means for transmitting,r a reciprocal movement to the pistons, an elect-ric motor for driving' said means, means actuated by a predetermined pressure in the compressed air receiving tank 'for automatically throwingr the compressinpr cylinder out of action, and means actuated by a predetermined vacuum in the other tank for throwing the vacuum producing cylinder out of action.

2. In a device ot the character described, an air compressor and a vacuum pum both driven in unison and by a single e ectric motor, a tank tonnect'ed with the Compressor, a second tank connected with the vacuum pump, and means for automatically breaking' the circuit through the motor when a predetermined pressure and vacuum is obtained in the respective tanks.

3. A device ot' the character described, comprising an air compressor and a vacuum pump, an electric motor adapted to drive said compressor and vacuum pump in unison, a tank in communication with the compressor, a` second tank in communication with the vacuum pump, means connected with the vacuum pumping unit for breaking the circuit through the motor when a predetermined va-r'uum is obtained, and means connected with the air compressingl unit for breaking' the circuit through the motor when :1 predetermined air pressure is obtained, said circuit brealv'intr means beilm1r only operable when they act. in unison or when Successively actuated.

4. A device ot' the character described,

ill

Leccese comprising an air compressing; unit ande vacuum pump, an electric motor adapted to vdrive the saule in unison, a tank connected with the air compressor, a tank connected with the vacuum pump, and] an electric motor circuit making and hrzaking mechanisin for each unit,` said units adapted to prepare and break the motor circuit. but neither being adapted to break l[he circuit unless it has been `prepared by the other unit.

5; A device of the character described, comprising an air compressor and a vacuum pump, a single means for driving the saine in unison, a tank connected with the comu presser, a second tank connected with the vacuum pump, and separate mea-ns connected with each tank and adapted to maintain 'iredetermined pressures therein-,said means adapted to jointly render the driving means inoperative.

62A device of the character described, comprising an air compressor and a vacuum pump, `a single .means for driving thesame in unison, a. tank connected with the comlncssor, a second tank connected with the vacuum pump, separate means connected with each tank and adapted to maintain predetermined pressures thereinLsaid means adapted to jointly render the driving 'means inoperative, and either means adapted to.

render the drivingii'neans operative.

7. A device of the 'character described, comprising an air compressor and a vacuum pump, means for driving the same in unison, a tank connected with the compressor, a second tank connected with the vacuum pump,

lmeans for automatically maintaining a predetermined pressure in the air tank, means for maintaining a predetermined vacuum in the second tank, and means actuated jointly by both oisaid last named means `for rendering the drivingl means inoperative, either ot said means also adapted to render the driving means operative upon a drop either in pressure or vacuum.

8. A. device of the character described, comprising an air compressing unit and a vacuum pump unit, an electric motor adapt-- ed to drive the same in unison, a tank connected with each unit one adapted to receive air under pressure and the other to be evacuated, ineens for automatically maintaining a predetern'lincd air pressure in one tank, and means for automatically maintaining` a ]nedetermined vacuum in the other tank, both of said last named means adapted to jointly break an electric circuit through the motor and either of said means adapted to close said circuit.

i). device ot' the character described,

comprising an air compressing unit and al vacuum pump unit, an electric motor adapt ed to drive the same 1u unison., a tank connected with each. unit one adapted to re unit adapted to be autoniatically opened or closed to permit either unit to charge or ceive air under 'pressure and the other to be evacuated, means for automatically 1na1ntaining a predetcrmined an' pressure in' one tank, means for automatically maintaining :i predetermined acuun in the other tank, 7G hoth olf said last named means adapted to jointly break an electric circuit through the motor and either ot said means adapted to close said circuit. and a relief valve for each evacuate each tank independent of the other.

1d An automatic lnotor control, comprising, in combination with an air con'ip'ressor and a vacuum pump, means actuated by the motor for driving,T `the compressor and lvactuuu pulnp in unison, separate tanks for each, separate automatically operated switches, each controlled hy the pressure in the adjacent tank, and means whereby the closingl of either switch willy close a circuit through themotor and. thefop'ening oit' both switches Will-he required to'hreak said circuit.

1l. A device of the character described, an air compressor, a vacuum pump, sepay rate tanks for each, a common driving motor :tor said' compressor and pump, a pair of switches connected in theelectric circuit of the motor, means automatically actuated .by the'pressure in one tank for opening,- and closing one switch, and means automatically actuated by the pressure in the other tank for opening and closing the 'other switch, said switches being so connected inv theP motor circuit that the closing of either .switch will close the motor circuit and the rocated in rnison by the crank shaft, a tank '.115`

connected 'with the vacuum pump cylinder and adapted to be evacuated thereby, means- -for transferring air from the, low 'pressure cylinder to the high pressure air compres singl cylinder, and a tank connected with 120. Y

said high pressure cylinder and adapted to he charged thereby.

13. AF two-stage air compressor and vacuuni'puinp, comprising a crank case, a crank shaft therein, a high pressure air co1n- 125 pressing cylinder on one side of the case, an aligned vacuum 'pump cylinder and a low pressure airl compressing cylinder on the other side ofthe crank case and in alignment with the high pressure air compressing cylinder, ay piston for each cylinder and all connected and adapted to be reciproeated in unison by the crank shaft, a tank connected with the Vacuum pump cylinder and adapted to he evacuated thereby, means for transferring air from the low pressure cylinder to the high pressure air compressing cylinder, a tank ,connected with said high pressure cylinder and adapted to be charged thereby, a relief valve connected with the compressing cylinder, and means for automatically opening the same when a predetermined air pressure is obtained in the connected tank.

14. A two-stage air compressor and vacuum pump, comprising a crank case, a crank shaft therein, a high pressure air compressing cylinder on one side of the case, an aligned vacuum pump cylinder, and a low pressure air compressing cylinder on the other` side of the crank case and in alignment with the high pressure air compressing cylinder, a piston for each cylinder and all connected and adapted to be reciprocated in unison by the crank shaft, a tank connected With the vacuum pump cylinder an'd adapted to be evacuated thereby, means for t"ansterrinbr air from the low pressure cylinder to the high pressure air compressing cylinder, a tank connected with said high pressure cylinder and adapted to be charged thereby, a relief valve connected with the vacuum pump cylinder, and means for automatically opening,r the same when a predetermined vacuum is obtained in the connected tank.

l5. A two-stage air compressor and Vacuum pump, comprising a crank case, a crank shaft therein, a high pressure air compressinf,r cylinder on one side of the case, an aligned vacuum pump cylinder and a low pressure air compressing cylinder on the other side of the crank case and in alignment with the high pressure air compressing cylinder, a piston for each cylinder and all connected and adapted to he reciprocated in unison by the cf'ank shaft, a tank connected with the vacuum pump cylinder and adapted to he evacuated thereby, means for transferringr air from the low pressure cylinder to the high pressure air compressingcylinder, a tank connected with said high pressure cylinder and adapted to be charged thereby, a relief valve connected with the compressing cylinder, means for automatically opening the same when a predetermined air pressure is obtained in the connected tank, a relief valve. connected With the vacuum pump cylinder, and means for automatically opening the same when a predetermined vacuum is obtained in the connected tank, said relierl valves beingturnable independentof each other.

EDWARD A. RK. 

